from Paris to Amsterdam

Air France and KLM both seem to
have around 5 daily flights from Paris Charles De Gaule airport (CDG) to Amsterdam (AMS) in
November 2009. This makes a total of around 10 daily flights.

Air France bought KLM, so they are one airline, but different brands.
Amsterdam Schiphol airport and Paris Charles De gaule airport are their
respective hubs.

An aternative to flying can be to take a high speed train
Paris CDG airport seems to be directly linked to Brussels Midi railway
station. From there you have several trains a day which go to Amsterdam
and stop just under the Schiphol Plaza at Amsterdam Schiphol airport
(AMS).

above: a KLM Boeing 737-400 in March 2010. Used on the route between Amsterdam and Paris.